Belgian authorities arrested five people on Friday in relation to deadly terrorist attacks in Paris and Brussels, but were still verifying whether they included sought-after men present during last month's attacks on the Belgian capital.
Last November, 130 people died in attacks on bars, restaurants, a sports stadium and a concert venue in Paris. On March 22, three suicide bombers killed 32 people at the Brussels international airport and the city's Maelbeek underground station.
Friday's arrests provide new indications of connections between the two sets of attacks. The Islamic State extremist group has claimed responsibility for both.
The arrested suspects include Mohamed Abrini, who had been the subject of an international arrest warrant since November, after police found video footage of him driving a Renault Clio car that was later used in the Paris attacks.
Surveillance cameras had recorded him together with Paris attack suspect Salah Abdeslam at a gas station in northern France two days before the attacks in the French capital.
The prosecution confirmed Friday that they had found Abrini's fingerprints and DNA in the Renault Clio, as well as at two addresses in Brussels linked to the Paris and Brussels attacks.
Abrini and Abdeslam had also rented an apartment outside of Paris where some of the suicide bombers stayed just before the attacks there, the Belgian prosecution said.
Following Abrini's arrest Friday, Belgian media reported that he was "more than likely" to be a fugitive attacker who fled the Brussels airport on March 22, leaving behind an explosive device.
But the prosecution said it was too early to say if they had arrested the suspect who has become known as the "the man with the hat," based on video surveillance images of him.
"At the moment, the investigators are verifying whether Abrini can be positively identified as being the third person present during the attacks in Brussels National Airport," said prosecution spokesman Eric Van Der Sypt.
On Thursday, Belgian prosecutors had asked for the public's help in gathering more evidence about the man.
Friday's arrests also included a man identified as Osama K, the prosecution said. He had been picked up in the German city of Ulm and brought to Belgium on October 3 in a rental car hired by Abdeslam.
Osama K - who also went by the alias of Naim al-Ahmed - was named by Belgian media as Swedish national Osama Krayem.
Osama K may have been present at the suicide bomb attack in the Maelbeek underground station, the prosecution said Friday. Media had previously reported about a second metro attacker, but officials had not confirmed it.
"The investigators are now verifying whether Osama K can be positively identified as being the second person present at the time of the attack in the Maelbeek subway station," the prosecution spokesman said.
That second person was seen in the company of the metro attacker Khalid El Bakraoui a while before he blew himself up, Van Der Sypt said. He was also filmed at a shopping mall in central Brussels buying bags used in the airport attack.
A second man identified as Herve B M was arrested on Friday morning with Osama K. Two other people were also arrested with Abrini, who was seized later in the day in the Brussels neighbourhood of Anderlecht, the prosecution said.
Police had earlier described Abrini, a 31-year-old Belgian national, as "dangerous and probably armed." His brother died in Syria after joining Islamic State, the Belga news agency reported.
Belgium's coordinating unit for threat analysis, OCAM, decided Friday to keep the country at security level 3 - the second-highest position - indicating a possible and likely menace, according to Belga.
The decision came after an evening meeting of Belgium's national security council, which includes Prime Minister Charles Michel, police chiefs and intelligence services, as well as OCAM.
Meanwhile, the Belgian royal palace praised those involved in Friday's operations.
"Congratulations and thank you to all those who enabled the arrest of two presumed terrorists," the palace wrote on Twitter.